Question

54.0 g Al reacts with 64.0 g O2 to

Answer 1

Answer:

102 g Al₂O₃

Explanation:

To find the mass of Al₂O₃, you need to (1) convert grams Al to moles Al (via molar mass), then (2) convert moles Al to moles Al₂O₃ (via mole-to-mole ratio from reaction coefficients), and then (3) convert moles Al₂O₃ to grams Al₂O₃ (via molar mass). It is important to arrange the ratios in a way that allows for the cancellation of units. The final answer should have 3 sig figs to reflect the given values.

Molar Mass (Al): 26.98 g/mol

Molar Mass (Al₂O₃): 101.96 g/mol

4 Al + 3 O₂ ---> 2 Al₂O₃

54.0 g Al          1 mole             2 moles Al₂O₃         101.96 g
--------------  x  -----------------  x  -----------------------  x  ----------------  =  102 g Al₂O₃
                        26.98 g               4 moles Al            1 mole